Recoil dampener



Nov. 2, 1943. J, c. TROTTER ET AL RECOIL DAMPENER 1 M mm W m m w... .L m a a m Z s mm 3 J50 w m m 2 M. i T L. m

Nov. 2, 1943. J. c. TRbTTER ET AL 2,333,398

RECOIL DAMPENER Filed May 20. 1 940 3 Sheets-Sheet 2 H mm 001 Wm WM J5 r m M %M Q QN m Nov. 2, 1943. J C TROTTER ETAL 2,333,398

RECQIL DAMPENER Filed May 20, 1940 3 Sheets-Sheet 3 FIG. 4.

Jim/0W5 JOHN C. TROTTER JACOB F SCHOELLKOP EZIZ" Patented Nov. 2, 1943 owns-o stares PATENT orrjlciz i I 2 ,333,393 V I RE-COIL nAMPannii. v w I Buffalo, N. Y., assignors toBeIIAitcraffCoi'poration,.Buflalo,.N. Y., a corporation of New York Aliplioation Mayw, 1940', Serial'No. 336,286

10 Claims.

Generally, this invention relates to recoil dampening, and more-particularlyto'the dampening of recoil in machineguns to be used in aircraft or other structures which are limited in space. Specifically, it covers a niount for machine guns that is provided with a-recoil dampening unit that will give a cushioning effectre'gardless of the angle at whieh the guns are being fired.

Heretofore, the devices whichhave-been provided to absorb the recoil of machine guns in aircraft havenot been especially practical. These prior mounts have been quite large and cumbersome and as a consequence. the op rator of the gun had difficulty in obtaining maximum accuracy in firing. Moreover, no recoil control units have been provided thatwould aiiord a cushioning result when the load is augmented or diminished by the weight of the gun at high and low angles of firing.

An object of this invention is to provide a machine gun mount for aircraft having a recoil dampening unit which is simple in construction and'operation and which can be cheaply manufactured.

Another object of the present invention is'to provide a recoil control for machine gun mounts which will afiord a cushioning effect when the load is increased or decreased by the weight of the gun at high and low angles of 'firing.

Yet another object of this invention is to-provide a recoil unit or machine gun mounts having a spring which absorbs-the principal amount of rec-oil and in which pneumatic means is included for taking care of increased loads.

A still further object of this invention is to'pro- Vide a novel recoil 'dampener for machine gun mounts which will not be affec'tedlay temperature changes.

effect the foregoing and other-advantageous objects, this invention-comprises supporting a machine gun or a pair of machine guns upon a light weight cradle or cradles which is mounted for horizontal movement in the fuselage of an airplane. A recoil dampening device is-attached in a substantially horizontal plane or planes slightly above or below the horizontal. As the angle of upward fire is'increased, the weight of the gun adds to the recoil load, thereby-increasing the distance of recoiltravel. rls 'a -consequence,

sible, and we accomplish the desired results by flirectionofthear'rows. c;

figure 4.31s a transversezsectionalyview when along the line i -'4 of Figure 1 lookingin the direction of the arrows; .1

Figure? 5 18a longitudinal .view'ofithe elemenis oonstituting'theirecoii dampener.

InEignuel, we haveshowrnaa of light weightcrad'lesi rand .2 supported by a vertical member 3; theilowerrendlois whioh is swivel-ed? in thefuselageaof an": airplane euthat :the

and. fi fllllld'i isladaptedqltomiose the forward end ofrthe tubesfl amirthe ma'mrends of. the tubesmre closedrlay arbraohdt Qwlfich supports; one of the operatmguhandles M. .Arlback piaitenzconstiuction amiafiring itriggerx H and L12, respectively, "are prowidedhttherearextremityaoi therc radlea Theznmailesil' and 25mm attachedto the support 3 for motamble saddle t3; the

structuralmletazils rolf whichahave been descriliedziin filmtterrapplicatlon Serial .No; 334 932, filed 'May H ll-9M3. 1 it c'anxrbe' seen in Figure :25that the are formedwith: longitudinal bones througil'rrwhizch extendzthe 1111,1254 anti 5..

maehine zgun 3| 5 isadapted-totbe zsupported by each n th'e orafihs' in .Fiagmie l. it willice noted t" a strap li-ltrii-dgestl'retuhes #and'fi and-is immed-with horses at each end to enabie stralpito izeciproeate on1 thedmbes; interme rliate the lextnemitiesraoii the istrafp" it: thereis formed ventical menibers .111 whilcncarrylugs em thatextend intoraperturesziormed in the gunzoas- It is necessaryto limit'this travel as much as 1 05-- "55 inc-tor attao mat e s untot mdle;

threaded extension 22 which is adapted to be received in an aperture formed in a flange 2'! which forms a part, of the saddle I3. A nut 28 is threaded onto the'extension 26 whereby therear section of the base 2| is secured to the flange 21, and consequently, the rear portion of the recoil unit 28 is anchored to the cradle.

A piston rod 29 carries opposed piston heads 3% and 3| which move in the cylinders 22 and 23, respectively. Each piston head comprises a leather cup 32 and a flanged metal plug 33 which is screwed onto an extension 3 1 of the piston rod.

Adjacent to the cylinder 22, the piston rod 29 is provided with a collar 35 which is held thereto by pin 31, and a washer 36 closes the inner end of the cylinder 23. A helical spring 38 encircles the piston rod 29 and one end bears against the collar 35 and the other end bears against the washer 36. The spring 29 tends to hold normally the piston rod and the piston heads in the position shown in Figure 3.

The collar 35 is formed with a pair of upstanding lugs 39. The forward portion of the machine gun casing is of course provided with bottom flanges lflanda bolt 4| extends through apertures 42and'43; provided in the flanges 4|) and lugs 39, respectively, whereby the gun is attached to the forward end of the piston 29. A nut 44 is threaded onto the end 'of the bolt 4|. for looking the parts in position.

It will be appreciated therefore that by reason of the strap l6 and the lugs 39 and the bolt 4| that the gun I5 is mounted in each cradle for forward and rearward movement during firing.

.Nipples 45'are provided inthe base 2| for pera In operation, when-the gunis fired, the piston rod 29 will move toward the rightin Figure 3 and the spring 38 "will compensate for most of the recoil. However, between the bottom of the piston head 3| and the base of the cylinder 23, there will be an airspace by virtue of air which will leak into the cylinder tzbetween the outer periphery of the piston head and the cylinder, and this air will afiord a cushion. to assist the spring. When the gun ceases firing, the spring 38 will move the piston rod towards the left and the air space between the closed end of the cylinder 22 and the piston head 30 will prevent .the head from striking the base of the cylinder until the air leaks out of the vent 46, or in other words, the construction functions as a dashpot.

On the other hand, when the guns are firing at a relatively high angle, it is necessary to take care of in addition to the, actual recoil of the gun the added weight of the gun, and the sudden compression of air in the cylinder 23 Will givea large increase in dampening to compensate for between the piston head3ll .and the base of; the

between the piston head and the cylinder base thereby eliminating hammering.

From the above description, it is believed readily apparent that we have provided a novel recoil dampening unit for use in light Weight mounts for machine guns which is highly emcient, simple to manufacture, and which consists of a limited number of essential working members. Furthermore, there is incorporated in the unit pneumatic means which will assist the principal recoil dampening member to take care of any additional loads which may be encountered in the firing of the guns. Furthermore, the unit is cheaper to maintain than the usual hydraulic dampeners and is not aifected in any way by changing temperature conditions. By having the cylinder 22, thus preventing mechanical contact 75 air cushions provided in each end of the unit we have been able to eliminate mechanical "hammering.

While we have shown and described the preferred embodiment of ourinvention, we wish it to be understood that we do not confine our selves to the precise details of construction herein set forthby' way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceedingthe scope of the appended claims.

We claim: p

1. Amachine gun assembly comprising, a cradle freely movablev from the horizontal, a machine gun mounted in the cradle for forward and rearward movement during firing thereof, a recoil absorbing; unit comprising spring means supported by the cradle at one end and operatively connected to the gun at the other end whereby the spring means will be compressed during the rearward travel of the gun to dampen the recoil of the gun, and an air cushion cooperating with the spring means to increasingly supplement the action thereof as the' firing angle of the gun above the horizontal is progressively increased.

2 A machine gun assembly comprising, a cradle freely movable from the horizontal, a machine gun mounted in the cradle for forward and rearward movement during firing, a recoil absorbing unitcomprising a cylinder attached to the cradle, a'piston and rod movable in the cylinder, a spring surrounding the piston rod, means attached to the gun and cooperating with the spring to compress the spring during rearward travel of the gun when fired to dampen the recoil, and means to effect an air cushion in the cylinder to increasingly supplement the action of the spring as the firing angle of the gun above the horizontal is progressively increased.

3. A machine gun assembly comprising, a cradle freely movable from the horizontal, a machine gun mounted in the crade forforward and rearward movement during firing, a recoil absorbing unit comprising opposed cylinders attached to the cradle, pistons movable in each cylinder, a common piston rod for each piston, a spring surrounding the piston rod, means attached to the gun and cooperating with the spring to compress the spring during rearward travel of the gun to dampen the recoil, and an air cushion in one of said cylinders to increasingly supplement the action of the spring as the firing angle movement a during firing, a recoil absorbing unit comprising opposed cylinders attached to the cradle, pistons movable in each cylinder, a common piston rod connecting each piston, a spring surrounding the piston rod, means attached to the gun and cooperating with the spring to compress the spring during rearward travel of the gun to dampen the recoil, an air cushion in one of the cylinders to increasingly supplement the action of the spring as the firing angle of the gun above the horizontal -is progressively increased, and a vent in the other cylinder whereby the air cushion therein will be gradually diminished when the gun is firing at angles below the horizontal thus eliminating hammering,

5. A machine gun assembly comprising, a cradle freely movable from the horizontal, a gun mounted in the cradle for forward and rearward movement during firing, a recoil absorbing unit comprising a cylinder attached to the cradle at a point adjacent to the forward end of the ma-- chine gun, a piston movable in the cylinder, a spring surrounding the piston rod, means attached to the gun and cooperating with the spring to compress the spring during rearward travel of the gun to dampen the recoil, and an air cushion in the cylinder to increasingly supplement the action of the spring as the firing angle of the gun above the horizontal is progressively increased.

6. A machine gun assembly comprising, a cradle freely movable from the horizontal, a gun mounted in the cradle for forward and rearward movement during firing, a recoil absorbing unit comprising opposed cylinders attached to the cradle at a point adjacent to the forward end of the machine, a piston movable in each cylinder, a piston rod connecting each cylinder, a spring surrounding the piston rod, means attached to the gun and cooperating with the spring to compress the spring during rearward travel of the gun to dampen the recoil, an air cushion in one of the cylinders to increasingly supplement the action of the spring as the firing angle of the gun above the horizontal is progressively increased, and a vent in the other cylinder-whereby the air cushion will be gradually diminished when the gun is firing downwardly thus eliminating hammering.

7. A machine gun assembly comprising, a cradle freely movable from the horizontal, a. gun mounted in the cradle for forward and rearward movement during firing, a recoil absorbing unit comprising a cylinder attached to the cradle, a piston movable in the cylinder, a spring surrounding the piston rod, a collar on the piston rod against which one end of the spring bears, lugs secured to the collar and attached to the gun whereby rearward movement of the gun will compress the spring to dampen the recoil, and an air cushion in the cylinder to increasingly supplement the action of the spring as the firing angle of the gun above the horizontal is progressively increased. g

8. A machine gun assembly comprising, a cradle freely movable from the horizontal, a machine gun mounted in thecradle for forward and rearward movement during firing, spring means connecting the cradle andthe gun whereby the spring will be compressed during the rearward travel of the gun and thereby dampen recoil and compressible means to increasingly supplement the action of the spring means as the firing angle of the gun above the horizontal is progressively increased.

9. A machine gun assembly comprising, a

cradle freely movable from the horizontal, a machine gun mounted in the cradle for forward and rearward movement during firing, spring means connecting the cradle and the gun whereby the spring will be compressed during the rear- Ward'travel of the gun and thereby dampen recoil, and a non-displaceable air cushion to increasingly supplement the action of the spring means as the firing angle of the gun above the horizontal is progressively increased.

10. A machine gun assembly comprising, a cradle freely movable from the horizontal, a machine gun mounted in the cradle for forward and rearward movement during firing, spring means connecting the cradle and the gun whereby the spring will be compressed during the rearward travel of the gun and thereby dampen recoil, a non-displaceable air cushion to increasingly supplement the action of the spring means as the firing angle of the gun above the horizon-' tal is progressively increased, and a displaceable air cushion which will gradually decrease when the firing angle of the'gun is below the horizontal.

JOHN C. TROTTER. JACOB F. SCHOELLKOPF, IV. 

